The present invention relates to tools for planning Signaling System 7 (SS7) communication networks.
An SS7 network is a packet data network used for out-of-band signaling to perform call set-up and tear-down, to implement Intelligent Network (IN) and Advanced Intelligent Network (AIN) services, to route traffic to interexchange carriers (IXCs), and to access database information needed to provide certain services such as 800, LNP, and LIDB. Core components of the SS7 network include switches called Signal Transfer Points (STPs). The STPs are interconnected with data links to form a core network.
Connected to each STP may be several different network elements. Signal Switching Points (SSPs or central offices) route calls. Points-of-Presence (POPs) serve as sources and sinks for network traffic. POPs provide alternate local carriers and IXCs with access to the Local Access and Transport Area (LATA) serviced by the STP. Network databases (DBs) support customer services such as IN and AIN.
Designing an alternative network includes adding, deleting, and moving network components, changing component capabilities, adding and modifying network services, and modifying connectivity between components. Changes to an existing network can create unintended situations. Removing an STP can leave elements disconnected from the network. Removing a database can eliminate a required service. Modifying connectivity can create load in excess of capacity on certain links and core network components. Designs are further complicated by changing loads and service requirements over time.
Traditionally, SS7 network planning has been accomplished through the use of spreadsheets. These spreadsheets only model a portion of the network such as, for example, the core network. Another difficulty is that load information has to be manually entered. Further, graphical display of the network and the effects of modifying the network are limited. As network size and complexity increases, the number of variables used to model the network is increasing beyond the capacity of the spreadsheet. Finally, a user attempting to create an alternative network does not have sufficient guidance and correctness validation.
What is needed is a system and method for modeling an SS7 network that provides greater capabilities. The tool should estimate STP service loads including demands generated by SSPs, POPs, and IN and AIN databases based on network traffic information. Estimated loads should be checked for accuracy based on additional network traffic information. For each study period in the SS7 network plan, service loads should be modified to reflect network growth.
It is a primary object of the present invention to provide an SS7 network modeling tool with greater capabilities than existing tools.
Another object of the present invention is to provide an SS7 network planning tool capable of estimating STP service loads including demands generated by SSPs, POPs, and IN and AIN databases based on network traffic information.
Still another object of the present invention is to check estimated service loads with network traffic information not used to estimate the service loads.
A further object of the present invention is to modify service loads for each study period in the SS7 network plan to reflect network growth.
In carrying out the above objects and other objects and features of the present invention, a method is provided for planning an SS7 network. The method includes automatically obtaining network traffic information from the network. Service loads are estimated based on a first set of network traffic information and service descriptions. Correction factors are calculated for service loads based on a second set of network traffic information. The correction factors are applied to estimated service loads to determine peak loads for each STP in the core network based on network traffic, component locations, and component connectivity.
In one embodiment, estimating service loads includes calculating a fractional size of each SSP homing on a given STP from the first set of network traffic information for each peak hour. LSTP local POTS loads for each peak hour are calculated. IN and AIN loads for each LSTP and each peak hour are calculated. POP loads for each LSTP and for each peak hour are also calculated. Growth is applied to service loads for each study period.
In another embodiment. calculating correction factors includes determining RSTP-LSTP correction factors for each RSTP-to-LSTP link by peak hour as the ratio of octets observed on the RSTP-to-LSTP link over a first time period to the estimated octets on the RSTP-to-LSTP link over the first time period. The estimated octets for each RSTP-to-LSTP link are based on the calculated LSTP loads. An RSTP message correction factor is determined by peak hour as the ratio of messages observed at the RSTP over a second time period to the estimated messages at the RSTP over the second time period. The estimated messages at the RSTP are based on calculated LSTP loads. POTS message correction factors are determined for each LSTP by peak hour as the ratio of POTS messages observed at the LSTP to the estimated POTS messages at the LSTP. POTS messages observed at each LSTP are based on a number of messages observed at the LSTP less a number of messages observed between the LSTP and connecting RSTP.
In a further embodiment, the first set of network traffic information includes traffic rates between each RSTP-LSTP pair, traffic rates between each POP-STP pair, and traffic rates into each STP.
Another method is provided for planning an SS7 network. Network traffic information is obtained from the network. Service loads are estimated based on a first set of network traffic information and service descriptions. Correction factors are calculated for service loads based on a second set of network traffic information. Correction factors are applied to estimated service loads to determine current peak loads for each STP in the core network. Peak loads are forecasted for each STP during each study period based on the current peak loads for each STP. Equipment capacity exhaustion is determined for each STP, network DB, and core network link during each study period for the network based on the forecasted peak loads. Costs for the network are determined for each study period.
A system for planning an SS7 network is also provided. The system includes at least one planning database having information on network traffic, network component locations, and network component connectivity. The system also includes a load module for estimating service loads based on a first set of network traffic information and on service descriptions, for calculating correction factors for service loads based on a second set of network traffic information, for applying correction factors to estimated service loads to determine peak loads for each STP in the core network, and for storing the determined peak loads in one of the at least one planning database. The system further includes a forecast module for determining equipment capacity exhaustion for each STP, network DB, and core network link during each study period and to determine network costs based on determined peak loads.
The above objects and other objects, features, and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings.